Connect with knowledgeable experts and enthusiasts on IDNLearn.com. Our experts are ready to provide in-depth answers and practical solutions to any questions you may have.
Sagot :
To determine which substance is incorrectly classified, let's systematically classify each one correctly based on its chemical properties.
1. HI (aq) - acid
- HI (hydroiodic acid) is a strong acid that completely dissociates in water.
- [tex]\( \text{HI} \rightarrow \text{H}^+ + \text{I}^- \)[/tex]
- It releases hydrogen ions (H⁺) when dissolved in water, hence it is correctly classified as an acid.
2. Na₂CO₃ - amphoteric
- Sodium carbonate is a salt formed from the reaction of a strong base (NaOH) and a weak acid (H₂CO₃).
- [tex]\( \text{2NaOH} + \text{H}_2\text{CO}_3 \rightarrow \text{Na}_2\text{CO}_3 + \text{2H}_2\text{O} \)[/tex]
- Sodium carbonate is a basic salt due to the presence of the carbonate ion ([tex]\(\text{CO}_3^{2-}\)[/tex]) which can react with water to form [tex]\(\text{OH}^-\)[/tex]:
- [tex]\( \text{CO}_3^{2-} + \text{H}_2\text{O} \rightarrow \text{HCO}_3^- + \text{OH}^- \)[/tex]
- Therefore, it is not amphoteric; it is a basic salt. This classification is incorrect.
3. HS⁻ - amphoteric
- Hydrogen sulfide ion ([tex]\(\text{HS}^-\)[/tex]) can act both as an acid and as a base, meaning it can donate or accept a proton.
- As an acid: [tex]\( \text{HS}^- + \text{OH}^- \rightarrow \text{S}^{2-} + \text{H}_2\text{O} \)[/tex]
- As a base: [tex]\( \text{HS}^- + \text{H}^+ \rightarrow \text{H}_2\text{S} \)[/tex]
- Therefore, [tex]\(\text{HS}^-\)[/tex] is correctly classified as amphoteric.
4. NH₄OH - base
- Ammonium hydroxide ([tex]\(\text{NH}_4\text{OH}\)[/tex]) is actually a solution of ammonia in water. In aqueous solution, it largely exists as ammonium ([tex]\(\text{NH}_4^+\)[/tex]) and hydroxide ions ([tex]\(\text{OH}^-\)[/tex]).
- [tex]\( \text{NH}_4\text{OH} \leftrightharpoons \text{NH}_4^+ + \text{OH}^- \)[/tex]
- It is a weak base, not an acid or salt. This classification as a base is correct.
5. KBr - salt
- Potassium bromide (KBr) is a salt that results from the neutralization reaction between the strong base potassium hydroxide (KOH) and the strong acid hydrobromic acid (HBr).
- [tex]\( \text{KOH} + \text{HBr} \rightarrow \text{KBr} + \text{H}_2\text{O} \)[/tex]
- KBr dissociates completely in water into potassium ([tex]\(\text{K}^+\)[/tex]) and bromide ions ([tex]\(\text{Br}^-\)[/tex]). Thus, it is correctly classified as a salt.
After reviewing each of the classifications, the incorrect classification is Na₂CO₃ which should be classified as a basic salt rather than amphoteric.
Therefore, the substance incorrectly classified is Na₂CO₃.
1. HI (aq) - acid
- HI (hydroiodic acid) is a strong acid that completely dissociates in water.
- [tex]\( \text{HI} \rightarrow \text{H}^+ + \text{I}^- \)[/tex]
- It releases hydrogen ions (H⁺) when dissolved in water, hence it is correctly classified as an acid.
2. Na₂CO₃ - amphoteric
- Sodium carbonate is a salt formed from the reaction of a strong base (NaOH) and a weak acid (H₂CO₃).
- [tex]\( \text{2NaOH} + \text{H}_2\text{CO}_3 \rightarrow \text{Na}_2\text{CO}_3 + \text{2H}_2\text{O} \)[/tex]
- Sodium carbonate is a basic salt due to the presence of the carbonate ion ([tex]\(\text{CO}_3^{2-}\)[/tex]) which can react with water to form [tex]\(\text{OH}^-\)[/tex]:
- [tex]\( \text{CO}_3^{2-} + \text{H}_2\text{O} \rightarrow \text{HCO}_3^- + \text{OH}^- \)[/tex]
- Therefore, it is not amphoteric; it is a basic salt. This classification is incorrect.
3. HS⁻ - amphoteric
- Hydrogen sulfide ion ([tex]\(\text{HS}^-\)[/tex]) can act both as an acid and as a base, meaning it can donate or accept a proton.
- As an acid: [tex]\( \text{HS}^- + \text{OH}^- \rightarrow \text{S}^{2-} + \text{H}_2\text{O} \)[/tex]
- As a base: [tex]\( \text{HS}^- + \text{H}^+ \rightarrow \text{H}_2\text{S} \)[/tex]
- Therefore, [tex]\(\text{HS}^-\)[/tex] is correctly classified as amphoteric.
4. NH₄OH - base
- Ammonium hydroxide ([tex]\(\text{NH}_4\text{OH}\)[/tex]) is actually a solution of ammonia in water. In aqueous solution, it largely exists as ammonium ([tex]\(\text{NH}_4^+\)[/tex]) and hydroxide ions ([tex]\(\text{OH}^-\)[/tex]).
- [tex]\( \text{NH}_4\text{OH} \leftrightharpoons \text{NH}_4^+ + \text{OH}^- \)[/tex]
- It is a weak base, not an acid or salt. This classification as a base is correct.
5. KBr - salt
- Potassium bromide (KBr) is a salt that results from the neutralization reaction between the strong base potassium hydroxide (KOH) and the strong acid hydrobromic acid (HBr).
- [tex]\( \text{KOH} + \text{HBr} \rightarrow \text{KBr} + \text{H}_2\text{O} \)[/tex]
- KBr dissociates completely in water into potassium ([tex]\(\text{K}^+\)[/tex]) and bromide ions ([tex]\(\text{Br}^-\)[/tex]). Thus, it is correctly classified as a salt.
After reviewing each of the classifications, the incorrect classification is Na₂CO₃ which should be classified as a basic salt rather than amphoteric.
Therefore, the substance incorrectly classified is Na₂CO₃.
We greatly appreciate every question and answer you provide. Keep engaging and finding the best solutions. This community is the perfect place to learn and grow together. Your questions deserve reliable answers. Thanks for visiting IDNLearn.com, and see you again soon for more helpful information.
